title: Glucose uptake, hexose monophosphate shunt activity, and oxygen consumption in cultured human retinal pigment epithelial cells.
abstract: Retinal pigment epithelium (RPE) was isolated from human donors with no known eye disease and normal-appearing fundi and was grown in culture. Population doubling times were measured for fifth passage RPE cells; the mean was 2.25 +/- 0.75 days and showed a correlation with the age of the donor. Metabolic studies were performed by perfusing the cells with 1-[13C]-D-glucose and monitoring the perfusate with magnetic resonance spectroscopy. Glucose uptake was 10.5 +/- 3.3 nmoles/min/mg protein. Lactate production from glucose was 20.0 +/- 5.00 nmoles/min/mg protein. The percentage of glucose through the hexose monophosphate shunt was 21 +/- 2%. Oxygen (O) consumption was measured at 20.1 +/- 4.1 nmoles O/min/mg endogenous and 14.5 +/- 4.8 nmoles O/min/mg with 10 mM glucose. These cells exhibit high rates of lactate production concomitantly with high oxygen consumptions and high flux through the hexose monophosphate shunt.
authors.affiliation: Department of Ophthalmology, Louisiana State University Eye Center, New Orleans 70112.
authors.forename: M V
authors.initials: MV
authors.lastname: Miceli
authors.forename: D A
authors.initials: DA
authors.lastname: Newsome
authors.forename: G W
authors.initials: GW
authors.lastname: Schriver
mesh_terms: D002455:Cell Division / Q000502:physiology; D002478:Cells, Cultured; D004734:Energy Metabolism; D005947:Glucose / Q000378:metabolism*; D006019:Glycolysis; D006801:Humans; D007773:Lactates / Q000096:biosynthesis; D019344:Lactic Acid; D009682:Magnetic Resonance Spectroscopy; D010101:Oxygen Consumption; D010427:Pentose Phosphate Pathway / Q000502:physiology*; D010477:Perfusion; D010857:Pigment Epithelium of Eye / Q000254:growth & development / Q000378:metabolism*
chemical_list: D007773:Lactates; D019344:Lactic Acid; D005947:Glucose